Horse or Zebra? Determining if You are Dealing With a Rare Diagnosis

"Common things are seen commonly" we are taught in our NP programs. While rare diagnoses certainly exist, if a more common condition fits your patients symptom profile this is the more likely culprit. But, sometimes the most common diagnosis isn't correct. How do you know which rare diagnoses you could be dealing with?

In the late 1940's, Dr. Thomas Theodore Woodward famously coined the term "zebra" for a rare medical diagnosis. "When you hear hoofbeats, think of horses not zebras", he instructed his medical students. By 1960, Dr. Woodward's words were widely known in medical circles and used to describe diagnoses made when another was more probable.

As medical providers, we all worry about missing zebras. Is your patient suffering from a migraine headache or do you have a case of pseudotumor cerebri on your hands? Are you dealing with a simple case of a backache or multiple myeloma? You patient presents with persistent fever and all of the standard labs return labeled "normal". What could be wrong? Fortunately, one company is seeking to help medical providers diagnose, or at least consider, the close to 7,000 recognized rare diseases.

FindZebra is a medical search engine specializing in rare diagnoses. Simply input the patient's symptoms into the search bar and a list of "zebra" diagnoses populates. Randomly selecting a few symptoms, I type "back pain, rib pain and fever" into FindZebra's search bar. Thoracic Outlet Syndrome, Tension Myositis Syndrome and Loin Pain Hematuria Syndrome" pop up as possible "zebras" capable of causing these symptoms. While FindZebra can't pinpoint a rare diagnosis exactly, it can help you know which direction to go when you suspect an out of the ordinary diagnosis.

While it might make your workday more interesting to hunt zebras in every patient, it's not practical. Reserve your zebra hunt for patients who aren't getting better with standard treatment or for those whose symptoms persist despite treatment. Consider zebras in patients who just don't look right although tests for more common conditions are negative. One of the problems with zebras is that once you see stripes, the disease has often progressed and may prove deadly. There's a fine line between practicing practically and knowing when something is off. FindZebra can help you consider rare diagnoses earlier in the process.